Spinner gets a null-value.

[Sven Sylta]

I don't understand why my spinnner is causing a nullpointerexception. Row 19 in the javacode. Is there somebody who have had the same problem or is able to figure it out? Thanks.

public class MainActivity extends ActionBarActivity {

	private Spinner spinner1, spinner2;
	
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
        
        spinner1 = (Spinner) findViewById(R.id.spinner1);
    	spinner2 = (Spinner) findViewById(R.id.spinner2);
    
    	spinner1.setOnItemSelectedListener(new CustomOnItemSelectedListener()); // Here is the problem.
    	//spinner2.setOnItemSelectedListener(new CustomOnItemSelectedListener());
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {
    	
        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);

            return rootView;
        }
    }

}

fragment_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
            
    <Spinner
        android:id="@+id/spinner1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:entries="@array/from_language" />
    
    <Spinner
        android:id="@+id/spinner2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:entries="@array/to_language" />
         
   <TextView
        android:id="@+id/text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/spinner2"
        android:text="@string/text_view" /> 
        
      <EditText
        android:id="@+id/type_word"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:hint="@string/type_word" />
        
</RelativeLayout>

activity_main.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.dictionary.MainActivity"
    tools:ignore="MergeRootFrame" />

[Ulf Dittmer]

You're setting "activity_main" as the layout, not "fragment_main" - which contains the spinners.

[Sven Sylta]

Ulf Dittmer wrote:You're setting "activity_main" as the layout, not "fragment_main" - which contains the spinners.

Thanks. I changed it to setContentView(R.layout.fragment_main); but it still didn't work. Then I removed this part from the onCreate()-method:

 /*  if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }*/

then, for some reason, it worked.